000 AXPZ20 KNHC 200936 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 524 UTC Mon Feb 20 2017 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURE... Gulf of Tehuantepec Gale Warning...High pressure will build over eastern Mexico behind a surface trough moving east across the western Gulf of Mexico on Tuesday, helping produce the next Gulf of Tehuantepec gap wind event. This event will be brief as winds peak near minimal gale force Tuesday night through early Wednesday morning. Winds will diminish below gale force Wednesday morning, and fall below advisory criteria Wednesday evening. Refer to High Seas forecast under AWIPS/WMO headers MIAHSFEP2/ FZPN03 KNHC for additional details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The ITCZ extends from 09N115W to beyond 02N140W. No significant convection is noted at this time. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see above for more on the Gulf of Tehuantepec gale force gap wind event. High pressure of 1020 mb centered near 27N121W extends a ridge southeast to near the Revillagigedo Islands. Gentle to moderate winds prevail over the offshore waters along the coast of Baja California. Light to gentle winds prevail elsewhere. Large northwest swell continues to push southeast while subsiding. Seas 12 ft or greater are now covering the area southwest of Baja California Sur. Seas are in the 10-11 ft range over the remainder of the offshore waters off the coast of Baja California. Seas are in the 8-10 ft range in the waters off southwest Mexico and 4-6 ft over the remainder of the offshore Pacific waters. Seas are in the 1-2 ft range over the Gulf of California. Seas will continue to subside off the coast of the Baja California, falling below 8 ft by early Tuesday morning. Another northwest swell will propagate into the area and once agin build seas above 8 ft off the coast of Baja California Norte Tuesday afternoon. High pressure ridge will strengthen west of the Baja California peninsula midweek to the end of the week. This will strenghten winds off the coast of the Baja California peninsula by weeks end. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Winds will pulse to moderate to locally fresh during the overnight hours through Tuesday night. Winds will then diminish by midweek. Gulf of Panama: North winds will pulse to moderate to fresh during the overnight hours through Monday night. Otherwise, winds will be in light to gentle range. REMAINDER OF THE AREA... A 1021 mb high is centered over the northern waters near 27N121W. A cold front is moving through the northwest waters, and winds have increased over this area with fresh to strong winds east of the front and strong to near gale winds west of the front. Northwest swells continue to propagate across the forecast waters. Seas 8 ft or greater are covering much of the area north of 10N and west of 110W. The cold front has ushered in a fresh set of northwesterly swells into the area, with seas reaching near 16 ft over the northwest waters. Seas will peak near 20 ft today over the far northwest waters before starting to subside. The front will continue to shift eastward while weakening, and is expected to dissipate late Tuesday. Winds associated to the front will diminish as the front weakens, and are expected to diminish below advisory criteria by late tonight. The northwesterly swells will continue to propagate southeastward, with seas 8 ft or greater covering much of the forecast waters north of 10N and west of 115W by midday Tuesday. Areal coverage of 8 ft seas will then decrease through the week, with only a residual area of 8 ft seas over the waters N of 20N and W of 135W by Friday evening. $$ AL